Among those who travel by automobile or truck extensively, it has become common practice to provide the vehicle with a citizen band (CB) radio receiver and transmitter. This equipment permits relatively easy communication between other vehicles in the area and, particularly on the highway, the CB radio operators forms a "fraternity" of those persons who are always willing to help one another and to warn other vehicles of impending problems on the highway. In this way, other vehicles can be informed of upcoming road problems, such as accidents, flooding, road construction, and the like. Since road hazards are usually related to a certain location on the highway, the warnings are usually related to the mileage markers along the highway, particularly on the high-speed federal highways or state highways. A difficulty that is encountered, however, has to do with the fact that not only is the person who is giving the warning not sure of his mileage position, but the receiving person is not sure of his present position either relative to the hazard. In many cases the mileage marker is obscured by snow or by darkness or has been removed by vandals; even when the markers are clear and available (both at the warning and the receiving end), one of the parties may be located between markers, which appear as mileage markers every mile and as tenths of miles in between. Even though some automobiles are provided with mechanical indicators of total mileage on the automobile, as well as being provided with odometers which can be set at the beginning of a trip, they are quite inaccurate. Secondly, they cannot be "set" quickly. Thirdly, they are incapable of operating in a decreasing mode. Fourthly, they are invariably difficult to read. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide an odometer capable of indicating mileage location on a highway to a high degree of accuracy.
Another object of this invention is the provision of an odometer capable of entering mileage quickly and accurately and operating either in the ADDING or the SUBTRACTING mode thereafter.
A further object of the present invention is the provision of an odometer having a readout formed of light-emitting diodes and constructed of solid state elements, including integrated circuits.
It is another object of the instant invention to provide an accurate odometer capable of operating in various modes, which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
A still further object of the invention is the provision of an odometer, particularly constructed for use in connection with CB communications and permitting the rapid introduction of known mileage marker readings, after which the odometer operates to give a continuous indication of location along the highway.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.